<html>
<head>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body></body>
<script>
  // This test goes forward by X pages, then back by Y pages,
  // then checks to see if that triggered a reload.
  // If it did, the document must have been discarded,

  // The current page number (stored in the URL search string)
  var page_number = location.search.substring(1) | 0;

  // The number of pages to go forward by.
  // This should be more than go_back_by, to ensure that
  // we actually do more than one back traversal.
  var go_forward_by = 24;

  // The number of pages to go back by.
  // This should be more than the default session-history.max-length pref,
  // to ensure that going back reloads the page.
  var go_back_by = Math.min(page_number, 21);

  if (history.length < go_forward_by) {
    // Keep loading new pages until we have loaded enough of them.
    location.assign("?" + (page_number + 1));
  } else if (page_number === 0) {
    // If we got back to the beginning, we must have triggered reloads.
    test(function() {}, "Forward then back triggered a reload.");
  } else {
    // Otherwise, go back.
    history.go(-go_back_by);
  }
</script>
</html>
